This is the second appearance of this case in this court. In Walker v. Fulton-DeKalb Hosp. Auth., 200 Ga. App. 750 (409 SE2d 529) (1991), we affirmed the trial court’s grant of summary judgment in favor of the Fulton-DeKalb Hospital Authority d/b/a Grady Memorial Hospital (“Grady”). The Supreme Court denied the Walkers’ application for certiorari. 202 Ga. App. 907.
Over two years later, Sharon and David Walker filed a motion to set aside the judgment on the ground that Grady had fraudulently obtained summary judgment by concealing from them (and from the court) that its contingency reserve fund plan had been amended and that it purportedly waived the charitable immunity defense. Grady denied any fraudulent concealment, and it moved to dismiss the Walkers’ motion to set aside or, alternatively, for summary judgment. The trial court denied Grady’s motion. Grady’s claim of attorney-client privilege with respect to certain information sought to be discovered by the Walkers was also rejected. The trial court certified both orders for immediate review, and we granted Grady’s application for interlocutory appeal.
It is undisputed that Grady has had some sort of self-insurance or contingency reserve program to protect its assets against malpractice claims since 1975 and that it has no commercial insurance coverage for such claims. Deposits from Grady’s operating budget to the fund are made under a trust agreement with a bank. The plan adopted in 1975 was designated a self-insurance plan.
In 1987, the Supreme Court decided in Ponder v. Fulton-DeKalb Hosp. Auth., 256 Ga. 833 (353 SE2d 515) (1987), that because payments from the fund would deplete Grady’s charitable assets, Grady’s self-insurance plan did not amount to “liability insurance” and Grady had not waived its charitable immunity when it adopted the plan. Id. at 835. In 1987, after the decision in Ponder, Grady adopted a new plan, the “Fulton-DeKalb Hospital Authority Contingency Reserve Fund.” It continued to have many of the same provisions, but it also contained a new, limited waiver of charitable immunity.1 That waiver provided that it was applicable “only to claims and suits as to which the claimant or plaintiff specifically acknowledges applicability of this limited waiver provision and alleges or asserts that the suit or claim is brought pursuant to the provisions of this section.” The plan ex*787pressly reserved all other immunities and provided that it “is not, and shall not be construed as, a general waiver of the charitable immunity doctrine. . . .” In Walker I (decided after the adoption of the contingency reserve fund plan), this court affirmed the trial court’s grant of summary judgment to Grady on three grounds: sovereign immunity, charitable immunity, and statutory immunity.
Even if the trial court’s grant of summary judgment to Grady was based only upon charitable immunity, this court had the power to affirm the judgment below on either of the two alternative grounds under the principle that a trial court’s judgment right for any reason will be affirmed.2 See Langford v. Royal Indent. Co., 208 Ga. App. 128, 134 (3) (e) (430 SE2d 98) (1993); Scott v. Hamilton Dorsey Alston Co., 206 Ga. App. 504, 505 (2) (426 SE2d 55) (1992). Therefore, even accepting appellee’s contention and assuming Grady’s charitable immunity was waived under the 1987 contingency reserve plan, if summary judgment in favor of Grady was proper either on sovereign immunity or statutory immunity grounds, it served no purpose to set aside the judgment based on the ground that charitable immunity had been waived because of the fraud alleged by the Walkers. In this case, therefore, the Walkers had the burden of showing that Grady was not entitled to summary judgment on any of the bases upon which the decision in Walker I rests. If the Walkers did not carry this burden, their motion was unavailing, even if correct as to the charitable immunity ground, and the trial court should have granted Grady’s motion to dismiss it. We therefore first address the two alternative grounds.
1. OCGA § 9-11-60 (h) provides that “[t]he law of the case rule is abolished; . . . provided, however, that any ruling by the Supreme Court or the Court of Appeals in a case shall be binding in all subsequent proceedings in that case in the lower court and in the Supreme Court or the Court of Appeals as the case may be.” If the decision of an appellate court thereafter becomes “incorrect” because the law changes — either because of subsequent case law or because of later-enacted statutes — it may not be binding precedent for other situations. However, between the parties to the original decision it remains binding. See Braner v. Southern Trust Ins. Co., 255 Ga. 117, 122 (335 SE2d 547) (1985); Gober v. Hosp. Auth. &c., 191 Ga. App. 498, 499 (2) (382 SE2d 106) (1989). Any other practice would result in constant relitigation of issues as the law continually evolves.
*788Although the Supreme Court’s recent decision in Thomas v. Hosp. Auth. of Clarke County, 264 Ga. 40 (440 SE2d 195) (1994), holding that hospital authorities are not entitled to sovereign immunity, is now “the law” as to this issue for all other litigants, it can have no effect on these parties because of the earlier contrary affirmance of summary judgment on this issue in Walker I. It is binding on this court as well as the trial court. The Walkers therefore may not successfully contend that Grady was not entitled to assert the defense of sovereign immunity in 1990. The Walkers may contend this defense has been waived, but they have the burden of establishing such a waiver. “ ‘Sovereign immunity is not an affirmative defense that must be established by the party seeking its protection. Instead, immunity from suit is a privilege . . . and the waiver must be established by the party seeking to benefit from the waiver.’ . . . [Cit.]” City of Lawrenceville v. Macko, 211 Ga. App. 312, 314 (1) (439 SE2d 95) (1993).
We find they have not carried this burden. The language of the 1987 plan makes clear that Grady expressly reserved all immunities to which it was entitled, except for a limited waiver of charitable immunity. It specifically and expressly provided that the plan was “not, and shall not be construed as, a general waiver of the charitable immunity doctrine [or] a waiver of . . . any other immunity as to any claim or suit against a covered person. . . .” Contrary to the Walkers’ argument, the waiver of sovereign immunity in another plan adopted by Grady after the trial court granted summary judgment in Walker I does not apply to them. A subsequent waiver is inapplicable to this action because a “waiver of sovereign immunity occurs at the time that the action arises.” Donaldson v. Dept. of Transp., 262 Ga. 49, 53 (3) (414 SE2d 638) (1992).
The entire premise of the dissent is also based upon the applicability to this case of the later, second revision of the plan, which was adopted in 1990, after the Supreme Court overruled Med. Center Hosp. Auth. v. Andrews, 250 Ga. 424 (297 SE2d 28) (1982). Although the dissent refers to this plan as the “post-Ponder plan,” the plan adopted in reaction to the Ponder decision was adopted in 1987. That is the plan applicable here, and not the 1990 plan. By the time the 1990 plan was adopted, summary judgment had been granted by the trial court and a notice of appeal had been filed.3
The Walkers’ reliance upon Litterilla v. Hosp. Auth. of Fulton County, 262 Ga. 34 (413 SE2d 718) (1992), in support of their conten*789tion that a self-insurance plan is sufficient to waive sovereign immunity, is similarly misplaced. First, Litterilla had not yet been decided when this court affirmed the trial court’s grant of summary judgment to Grady. Second, Litterilla is distinguished on its facts. The hospital in that case had purchased an “umbrella” liability policy to supplement its self-insurance plan, and the Supreme Court held that “the Umbrella Liability Policy together with the trust fund created by the Hospital . . . constitutes ‘liability insurance protection’ within the meaning of the constitutional provision [regarding waiver in effect at the time] and therefore acts as a waiver of sovereign immunity.” Id. at 36. Moreover, in Logue v. Wright, 260 Ga. 206 (392 SE2d 235) (1990), the Georgia Supreme Court held that counties are not authorized to waive sovereign immunity by creating such self-insurance plans because “under the statutes dealing with liability insurance for government employees and officials, only state self-insurance plans will waive sovereign immunity.” Id. at 209. Therefore, under the authority of Logue, Grady’s plan cannot operate to waive sovereign immunity.4
Because the Walkers had the burden of establishing waiver of the defense of statutory immunity and failed to do so, the prior grant of summary judgment on the statutory immunity ground, affirmed by this court in Walker I, may safely stand. It is therefore unnecessary to consider the other two grounds. The trial court erred in denying Grady’s motion to dismiss or for summary judgment.
2. It follows that we need not address Grady’s contention that the trial court erred in ruling that the documents sought to be discovered by the Walkers were privileged.
Judgment reversed.
Birdsong, P. J., McMurray, P. J., Andrews, Johnson and Ruffin, JJ., concur. Beasley, C. J., Pope, P. J., and Blackburn, J., dissent.The new plan also changed the payment limits for any single occurrence and for the overall annual total payable for all occurrences. Those changes are not material to this appeal.
Contrary to the Walkers’ argument that this court’s holdings as to sovereign immunity and statutory immunity are dicta, “ ‘where there are two grounds, upon either of which the judgment of the trial court can be rested, and the appellate court sustains both, the ruling on neither is obiter, but each is the judgment of the court and of equal validity with the other.’ [Cits.]” Dooly v. Gates, 194 Ga. 787, 793 (22 SE2d 730) (1942).
We note also that, having decided that “the plan” waived all immunities, the dissent nevertheless fails also to address the issue then created by Grady’s disclosure to the Walkers that a plan was in effect, and the Walkers’ subsequent failure to conduct further discovery that would have revealed its exact terms.
This court so held in Culberson v. Fulton-DeKalb Hosp. Auth., 201 Ga. App. 347, 348 (1) (b) (411 SE2d 75) (1991). But see Thomas v. Hosp. Auth. of Clarke County, supra, 264 Ga. 40, 41 (“hospital authorities, because they are neither the state nor a department or agency of the state, are not entitled to the defense of sovereign immunity”). We have held, infra, that Thomas does not apply here.